The present invention relates to a telecommunications apparatus with a plurality of telephone terminal devices and a telephone exchange unit for control of the telephone communications between the telephone terminal devices and between the telephone terminal devices and a fixed telecommunications fixed network, in which the telephone terminal devices are operable by a connected computer. It also relates to a method of telecommunications between the telephone terminal devices and between the fixed telecommunications network and the telephone terminal devices.
Telecommunications systems, which have their own central exchange unit, to which a plurality of telephone terminal devices are connected, are increasingly connected in fixed telecommunications networks. The telephone exchange unit controls the connection of incoming calls with the desired telephone terminal devices and the connection of the telephone terminal devices with each other. The telephone terminal devices communicate with the telephone exchange unit by means of a telephone channel. There is a frequently occurring requirement that the telephone terminal device should not be operated separately, especially when data is input to a computer and, if necessary, output from the computer during a telephone contact, for example as is the case with telephonic information services or telephonic customer contacts.
In this situation it is appropriate to perform certain operations of the telephone terminal device themselves by means of the computer, for example the relaying of an incoming call, the making of a conference connection, the turning on of a speaker device. For this purpose it is known to provide the telephone terminal device with a computer interface, in order to be able to transmit operating signals that are analyzed by the microprocessor of the telephone terminal device to the telephone terminal device by means of the computer.
Conventionally besides the telephone terminal devices computers also are connected to the telephone exchange unit. For this purpose a suitable bus, which is called a CTI link (CTI=computer telephone interface), exists. A communication between the computer and the telephone exchange unit occurs in a data channel thus formed, for example in order to perform a fax operation from the computer and to immediately undertake an information exchange by means of data via the telephone exchange unit. Basically it is conceivable, to permit performance of control functions directly by the telephone exchange unit by means of the computer which is connected via the data channel with the telephone exchange unit, which would otherwise be performed by manual operation of the telephone terminal device. This has the disadvantage that the microprocessor of the concerned telephone terminal device being controlled receives no information regarding the change of the configuration of the telephone exchange unit because of the control signals from the computer, so that the changed configuration is detected in the connected telephone terminal device as interference and can lead to an interruption of the connection.
The remote operation of a telephone terminal device by means of a computer can thus take place in the known telecommunications arrangements only when the computer is directly connected to the telephone terminal device. This known arrangement has the disadvantage that a special connection must be made and that the telephone terminal unit is only operated in an imperfect manner during remote control operation. For example, an operating signal can only be provided in a display of a telephone terminal device in manual operation, but in the remote control operation by means of a computer.